In the area of E-mobility applications plug connectors including an electrical locking function are known and provided normatively for transmitting electrical energy from a charging device for charging a vehicle's secondary battery provided in the electric vehicle.
To this end a device plug can be provided at the charging device and at the electric vehicle, respectively, such that by means of a connecting cable comprising at both ends a cable connector corresponding to the device plug an electrical connection can be established between the charging device and the electric vehicle.
Realizing this electrical locking function can include mechanically retracting a cylinder pin perpendicular to the plug direction of the plug connector plugged completely up to its limit, wherein the cylinder pin is capable of penetrating the device plug and the cable connector in a radial direction through corresponding bores, such that in the locking process a tight fit in an axial direction can be created. In this way a manual disengagement of the connected plug connectors is prevented in order to avoid according to safety aspects that plug connectors under load cannot be separated from each other or a yet incomplete charging process of the vehicle's secondary battery will not be not interrupted. Normally the cylinder pin is driven electromechanically, for example by means of solenoids or actuators with an upstream mechanic.
Herein, solenoids often operate against a mechanical spring and need to be retained permanently in an end position, i.e. when the plug connectors are locked, under consumption of electrical energy. When the voltage supply fails the spring opens and unlocks the system automatically. It is, however, disadvantageous that the power required for activation has to be provided constantly by a control electronics and often amounts to several watts.
On the other hand actuators are typically driven by short alternately polarized current pulses and after reaching their end position remain passively in their locking and unlocking position, respectively. This means, that actuators do not consume any energy even in the locked state, for example during the charging process of the vehicle's secondary batteries of the electric vehicle. During a power breakdown event, particularly of the charging device, however, the actuators can no longer be driven, resulting in a permanent undesired locking state of the plug connectors.
A spring supported resetting of the actuators from the locking position to the unlocking position often is impossible or can be implemented only with extensive efforts for mechanical reasons. Even a pure mechanical emergency unlocking means which is operable, for example, by means of a cable wire often is excluded because to this end a permanent access to this unlocking means is required which, however, although principally possible, is often not desired for reasons of misuse, particularly at public charging facilities.